Global Merchant Shipping Fleet: Vessel Types, Sizes, and Key Statistics

Shipping continues to be the most cost-effective method of moving goods over long distances. The continued globalization of trade combined with more efficient shipping technologies will likely result in the continued dominance of global trade by shipping. Currently, the world’s merchant shipping fleet consists of approximately 91,000 ships owned by more than 250 companies representing approximately 1.7 billion dwt (see later) with an average ship age of twenty-two years. In 2010, shipping employed over 1.4 million seafarers from 150 states. Table 8.1 provides a summary of the various ship classifications and sizes; however, the primary types of modern merchant ships are as follows:

TABLE 8.1 Global Ship Classifications and Size

Bulk carriers transport raw materials, including grain, ore, and coal. The bulk cargo fleet represents 43.1 percent of the total global ship fleet by vessel number.

Tankers transport crude oil, chemicals, cooking oils, and other liquids. Some specialized tankers carry cargos such as liquefied natural gas. The tanker fleet represents 27.9 percent of the total global ship fleet by vessel number.

Container ships carry containers that can be onloaded and off-loaded onto trucks and trains (referred to as “intermodal freight transport” or “fully cellular”). The size of container ships is based on how many 20-feet equivalent units (TEU) containers the ship can transport. The largest container ships currently have up to an 18,000 TEU capacity. The container fleet represents 13.5 percent of the total global ship fleet by vessel numbers.

General cargo ships include refrigerated cargo, specialized cargo, roll-on/roll-off (ro- ro—used to transport vehicles), and other types of special-purpose ships. The general cargo fleet represents 4.2 percent of the total global ship fleet by vessel numbers.

Ferries and cruise ships transport passengers, cars, and commercial vehicles.

Specialist ships include supply vessels, tugs, icebreakers, and research vessels.

Several different measures are used to classify ship size. Deadweight tonnage (dwt) is the number of tons (2,240 lb) of cargo, stores, and fuel a vessel can transport. Cargo tonnage is the weight of cargo carried by the vessel, measured in American short tons (2,000 lb), English long tons (2,240 lb), or metric tons (1,000 kg). Gross tonnage (GT, G.T., or gt) is the volume of a vessel’s enclosed spaces divided by 100. A GT is 100 ft³. Gross tonnage is not a measure of mass (weight), but volume. Net tonnage (NT, N.T., or nt) is the gross tonnage minus all areas of a ship not used to transport cargo, which is also referred to as “earning space.” Net tonnage is not a measure of mass (weight) either, but volume.